ZendService\Amazon

By default, all Amazon EC2 instances are assigned two IP addresses at launch: a private (RFC 1918) address and a
public address that is mapped to the private IP address through Network Address Translation (NAT).

If you use dynamic DNS to map an existing DNS name to a new instance’s public IP address, it might take up to 24
hours for the IP address to propagate through the Internet. As a result, new instances might not receive traffic
while terminated instances continue to receive requests.